In a refrigeration cycle of air conditioner, a refrigerant is circulated in the cycle while changing in three states, that is, liquid phase, gas-liquid twin phase and gas phase. A dryer for refrigeration cycle filled with such adsorbent as zeolite for adsorbing moisture has been used in an air conditioner. However, in its method of use, it has been preferably placed in such location that the refrigerant is at a low temperature, and the power loss is smaller as the refrigerant is closer to liquid phase, which has been a desirable condition of use. Even in the case of changing over between cooling and heating operations, it has been often operated with the refrigerant flowing in one direction.
In a refrigeration cycle of air conditioner, however, because of the desirability for designing with reduced size, it is desirable for components to have a resistant property to severe conditions. In addition, as the refrigerant used has been changed from hydrochlorofluorocarbon (HCFC) to a substitute refrigerant, hydrofluorocarbon (HFC), the pressure of the refrigerant has been increased about 1.6 times, and it has been desirable to sufficiently consider a resistance to vibration associated with such increase in pressure of the refrigerant.